A private space company offering room on inflatable space habitats for research has found a robust international market, with eager clients signing up from space agencies, government departments and research groups.

Space entrepreneur Robert Bigelow, chief of Bigelow Aerospace, has been busy marketing his private space modules, an outreach effort leading to six deals being signed with clients this year.

The deals, in the form of memorandums of understanding, involve Japan, the Netherlands, Singapore, Sweden, Australia and the United Kingdom.

"These are countries that do not want to be hostage to just what the International Space Station may or may not deliver," Bigelow told SPACE.com in an exclusive interview. [Bigelow Aerospace plans private moon bases.]

Bigelow founded Bigelow Aerospace in 1999, headquartered in Las Vegas, drawing upon his construction, real estate, and hotel savvy to forge the use of expandable space structures. To date, he has spent more than $200 million to hammer out his business plan for space.

Steel in the air

Some of that private cash was spent to hurl two of his firm's prototype expandable space modules into orbit. The company's Genesis 1 and Genesis 2 test modules, lofted in July 2006 and in June 2007, served as forerunners to ever-larger and human-rated space structures.

More recently, some $20 million of Bigelow?s cash has flowed into a sprawling, 185,000 square-foot expansion to his North Las Vegas facilities, a building that enables the churning out of bigger space habitats.

"That expansion is currently under way. We broke ground a few months ago. We've got a lot of steel in the air," Bigelow said. But more newsworthy, he said, is the signing of memorandums of understanding to make use of the company?s expandable space structures.

"I'm also in the middle of developing a new client leasing guide that will be available toward the end of the year. It will have new and exciting pricing opportunities that are very dramatic," Bigelow said."We want to open up the window and doors for a lot of participation for folks that need to spend less."

Robust and global

A question that continues to float through the halls of NASA and the Congress: Is there a commercial market for utilizing space?

"We?ve got a very certain and loud answer to that. Not only is there a commercial market, but it's a one that's robust and global," said Michael Gold, director of Washington, D.C., operations and business growth for Bigelow Aerospace.

The memorandums have been signed with what Gold said the firm terms as "sovereign clients" ? the result of a relatively modest effort to pulse "international astronautics opportunities" with countries large and small.

Bigelow said what they have found is a hunger by clients to do activities in space far beyond just microgravity experimentation.

"That is what this new leasing guide is going to expose," Bigelow said. "It?s encouraging to see the enthusiasm. They all have different reasons, different ways in which they see using our facilities ? what I call 'dynamic assets' in the new leasing guide ? to benefit them. It can change the face of a nation."

Gold said that some $100 billion has been spent on the International Space Station.

"All that money to create an amazing laboratory environment in space ? but when it comes to actually doing something with it, what?s being spent on utilization is relatively paltry," Gold emphasized. "It?s like purchasing a Lamborghini and then spending five dollars on gas."

While countries in Asia and Europe take commercial advantage of space, "my fear is that this could become yet another extremely lucrative economic opportunity that is engendered here ? and then shipped overseas," Gold cautioned. "The U.S. Congress should spend less time questioning the business case of the commercial market. They need to spend more time trying to figure out how to grow that market and ensure that it happens here in the United States."

Tried and true

Still, while there is "palpable enthusiasm," according to Gold, by clients to use Bigelow space facilities, getting customers back and forth to low-Earth orbit remains to be solved.

Boeing and Bigelow Aerospace have been working together on access to a Bigelow-provided Orbital Space Complex, making use of Boeing's CST-100 capsule being pursued under NASA?s Commercial Crew Development (CCDev) program.

CST-100, for Crew Space Transportation, is being designed to fly without crew or with as many as seven astronauts. [Video: Boeing's New Spacecraft]

Gold underscored the "great potential" of the Atlas 5 booster.

"We have much more confidence in regards to the crew transportation solution since there is, arguably, no system safer, more reliable and more cost-effective than leveraging the tried and true Atlas 5 with a capsule built by Boeing on top of it," he said. "It has a track record. It exists. That?s a message that has resonated quite well with the international clients."

There has been discussion, Gold said, that cost savings and safety are mutually exclusive.

"The Atlas 5 is an example of how those two actually go hand in hand. That rocket?s flight heritage will create the safety that we demand and our customers require," he concluded.

Leonard David has been reporting on the space industry for more than five decades. He is past editor-in-chief of the National Space Society's Ad Astra and Space World magazines and has written for SPACE.com since 1999.